I. Field
The following description relates to wireless communications, in general, and to physical cell identifier (PCI) collision detection in wireless communication systems, in particular.
II. Background
Wireless communication systems are widely deployed to provide various types of communication. For instance, voice and/or data can be provided via such wireless communication systems. A typical wireless communication system, or network, can provide multiple users access to one or more shared resources (e.g., bandwidth, transmit power). For instance, a system can use a variety of multiple access techniques such as Frequency Division Multiplexing (FDM), Time Division Multiplexing (TDM), Code Division Multiplexing (CDM), Orthogonal Frequency Division Multiplexing (OFDM), and others.
Generally, wireless multiple access communication systems can simultaneously support communication for multiple user equipment (UEs). Each UE can communicate with one or more base stations (BSs) via transmissions on forward and reverse links. The forward link (or downlink (DL)) refers to the communication link from BSs to UEs, and the reverse link (or uplink (UL)) refers to the communication link from UEs to BSs. In unplanned and self organizing networks (SONs), there is a good probability that a given area is covered by more than one cell with the same physical cell identifier (PCI), which will be referred to as a “collision” herein. Collisions can result in ambiguous operation, for example during handover. One method of improving the likelihood of collision-free operation is to configure UEs to report collisions. Collision reporting by UEs can be facilitated if UEs have collision detection capability. This can be achieved to some extent in asynchronous networks, where the neighbor cell search detects both of the cells of interest at different time offsets. However, such methods may not work in synchronous networks because the Single Frequency Network (SFN) nature of the signals involved during cell search can result in the two colliding cells appearing as one cell to the UE. Accordingly, systems, apparatus and methods for enabling PCI collision detection in synchronous networks are desired.